The invention relates to a ground-based wireless cellular communication system, to an airplane equipment being adapted to provide in-flight broadband mobile communication services, as well as to a corresponding method. The invention also relates to a communication system comprising such a ground-based wireless cellular communication system and at least one such airplane equipment.
For efficiently providing broadband (and/or narrowband) communication services to airplanes (to be used by passengers, crew, and/or for automatic exchange of (airline) operational data), spectrum efficiency in the ground-to-air and air-to-ground communication should be high to offer real broadband services and to keep the number of ground-based base stations and/or required transmission resources (e.g. licensed spectrum) low while serving a large number of airplanes at the same time. Moreover, airplane passengers should be enabled to use their own regular communication devices (phones, laptop cards, etc.) for performing the broadband communication.
For providing such an in-flight broadband communication, a satellite-based system may be used, relying on communication with satellites in geostationary orbits. However, such a system is expensive and typically has very high latency, thus having a negative impact on service quality. Moreover, existing L-band solutions do not offer the capacity required for upcoming air traffic demands.
A better solution would be a ground-based cellular system that uses base station antennas with broad main lobes in the antenna characteristics to cover large portions of the sky. The multiple-access scheme for serving a number of airplanes would be a time-division multiple-access (TDMA) scheme, or a frequency-division multiple-access (FDMA) scheme, or a combination of both. However, these multiple-access schemes do not account for the spatial separation of the served airplanes within one cell. Thus, these schemes do not reach the theoretically possible spectrum efficiency.